IMHO part of the problem is definitely due to shutdown of nuclear, rapid expansion of renewables while keeping costly (due to EU CO2 emissions trade) coal plants going. Most other countries used renewables to replace coal plants while keeping existing nuclear around. Germany did the opposite.
But the international comparison is not as simple as the power price, there's a lot of infrastructure that is subsidized by other taxes and not power price directly. Not that those are any lower in Germany.
Prices are also lower than in France, but not the residential prices which are affected by taxes and fees while capped in France.
It's mostly taxes and taxes being taxed additionally by other taxes, a good chunk of that was/is for transitioning to green energy and subsidizing home solar.
According to [1], about 75% of the price per kw/h in Germany is shared between the producer of the electricity and the owner of the network. As the market for electricity is completely liberalized, those can be any of hundreds of companies.
The rest, about 25% are various taxes and surcharges.
While renewable energies are responsible for some of the above average electricity prices in Germany, the recent price surge is mostly due to the high price of natural gas. Germany electricity prices are fixed by a system of auctions, where the demand at any given point in time is fulfilled by the producers willing to charge the least amount of money, but the actual price is set by the most expensive bid that is still required to satisfy demand. Due to the peculiarities of the electricity markets, this often ends up being natural gas power stations and natural gas has become crazy expensive due to Russia cutting off exports to Germany.
[1] https://strom-report.com/strompreise/strompreis-zusammensetz...
The price hasn't budged -- is that because it only reflects changes in gas pricing long-term, or is someone else pocketing the part the state used to take?